Plastic liners are commonly used in pipes and conduits to provide a corrosion resistant interior surface to the pipes or conduits, which may comprise steel or other metal that is susceptible to corrosion, deterioration, or other undesirable affects in the presence of the substance carried by the pipe. It is also generally known that plastic liners can be permeable in the presence of some substances and environmental conditions, such that gases may migrate or permeate to an interface between the liner and the pipe and, over time, cause deterioration and damage to the liner and pipe. To release these gases, a hole may be drilled through a wall of the pipe without puncturing the liner. However, a hole in the metal pipe can be susceptible to corrosion and thus limit the release of the gases, among other issues.